Today, bicycles enjoy wide recognition and favorable acceptance as a means of transportation. Bicycle design and construction has evolved tremendously over the years, and further evolution will likely continue long into the future. Exemplary of today's recumbent bikes are those shown in U.S. patent application Ser. No. 08/226,898, filed Apr. 13, 1994, now U.S. Pat. No. 5,486,015, and U.S. patent application Ser. No. 08/572,239, filed Dec. 13, 1995, now U.S. Pat. No. 5,823,554, both of which are incorporated herein in their entireties by reference.
In the early days of development, both steering and powering functions for the typical bicycle were carried out via the front wheel. A typical steering arrangement included a handlebar, attached atop a steering column, as a means for operator controlled steering of the vehicle. In this regard, the handlebar/steering column arrangement was designed to rotate in concert with the front wheel. Any manual rotation of the handlebar effected an identical angular rotation of the front wheel. For motion, early systems typically supplied driving power, derived from a rider's leg work, directly to the front wheel. In this regard, the drive systems, generally included a pair of rider engagable foot pedals. One pedal was positioned laterally outward of, and alongside, each outer face of the wheel. Connection means were provided to rigidly attach the pedals at opposing ends of the front wheel axle.
Although effective for certain limited purposes, the early direct drive systems were characterized by various disadvantages. For example, the typical human operator was physically incapable of rotating the front wheel assembly, via the foot pedals, at such a rate (revolutions per minute) as required in order to achieve high vehicle speeds (i.e., more than 15 mph). Further, high speed travel could not be achieved even when such a direct drive system was used in combination with a large-diameter front wheel (e.g., five feet). Another disadvantage, which was characteristic of the early direct drive systems, was incurred due to the rigid attachment of the foot pedals at the front wheel axle. Such attachment required that the pedals rotate about the vehicle's steering axis upon rotation of the front wheel. This characteristic made vehicle steering maneuvers highly cumbersome for the operator.
Subsequent design efforts, aimed at permitting an increase in top vehicle speed without requiring the use of a large-diameter front wheel, eventually lead to the introduction of gears into the vehicle drive system arrangement. Achievable bicycle top speeds increased tremendously as a result. The developed sprocket and the various systems of sprockets, additionally, permitted the foot pedals to be fixed with respect to the vehicle frame instead of at the front wheel axle. Accordingly, the problems due to pedal rotation during steering could be avoided. The great successes enjoyed through the use of sprockets in the various bicycle operational systems prompted still further development efforts. Today, developers continue such efforts to create new and/or improved gears and gear arrangements capable of satisfying a variety of targeted needs and goals.
Numerous and varied additional changes and improvements in bicycle design have been observed over the past century. The typical bicycle of today generally includes a metal frame mounted on two wire-spoked wheels with one behind the other, a seat, handlebars for steering, and a pair of pedals by which it is driven. The majority of present day bicycles are constructed so that steering is accomplished via the forwardly positioned wheel and drive (power) for the vehicle is provided via the rearwardly positioned wheel. The overall length of such arrangements tend to exceed five feet. The vehicle weight is sometimes minimized by utilizing light weight materials, such as aluminum or fiber reinforced resins. Bicycle constructions which employ such materials can achieve vehicle weights as low as 10 pounds.
In spite of the widespread acceptance of bicycles as a means of transportation highly useful for many purposes, riders nevertheless often encounter problems upon reaching a destination point. For example, adequate facilities may not exist at a particular destination for storing the bicycle. Unfortunately, when a bicycle is temporarily parked and left unattended, it often becomes a target for theft and/or vandalism. Another problem can be encountered if the bicycle is used during, or in making, only a limited portion of a trip. In such a situation, the use and/or presence of the bicycle, especially a large and/or heavy one, will not always be desirable. For example, it may become necessary for a rider to carry the bicycle onto a different transportation vehicle for a time (e.g., a bus, van, train, plane, etc.). Such a situation could arise when the only reasonable means available to get to a particular desired location is by way of a common public transportation vehicle, but the rider contemplates a future need to use the bicycle after arriving at the location. It is not only inconvenient to hand carry presently known ordinary bicycles, but also those constructed of very light weight materials. This is due to the fact that many problems arise primarily as a result of vehicle length. Typical vehicle lengths are often equal to, or greater than, average human height. Thus, problems caused merely by the spatial outlay of a vehicle can deter or prohibit a rider from carrying it about and/or stowing it safely away during periods of nonuse (e.g., while at the workplace).
Development efforts, focused at reducing the vehicle carrying configuration length and width, have given rise to bicycle designs incorporating various folding schemes. Although the known folding bicycle designs exhibit a number of differences from the typical features of bicycles, they have all continued to utilize the typical basic steering and power drive arrangement employed with ordinary bicycles. So far, the reductions in carrying configuration size (volume) achieved by the known folding bicycles have not proven sufficient to promote their general recognition and acceptance.
In order to operate a typical bicycle, a force (power) must be imparted by the rider's legs towards the vehicle pedals. Generally, this operating force extends in a substantially vertical direction. Accordingly, the rider usually assumes a riding position which facilitates the application of such force. The usual position assumed by the rider tends to make the overall vehicle/rider height greater than four feet. As a consequence, a large frontal view cross sectional area of the rider's body is exposed which acts as a source of drag.
There is a known bicycle design-type which reduces the frontal cross sectional area exposed by a rider, as compared to that encountered with the more typical bicycle constructions. Such vehicles are known as recumbent bicycles. Recumbent bicycles are designed so that the rider assumes a lay-back position during vehicle operation. Recumbent bicycles have been the predominant design-type used by riders in setting the currently held short distance speed records. Despite their successes, recumbent bicycles are recognized to present certain problems of their own. Recumbent bicycles equipped with typical front wheel steering and back wheel drive require the use of long drive chains which are positioned under the rider. Unfortunately, such drive chains are a potential source of drag since they tend to add to the vehicle height and, thus, to the frontal view cross sectional area.
According to basic mechanical theory and physics, when the direction of the applied force on an object is perpendicular to the direction of travel, no energy (momentum) is transferred. Without the energy/momentum transfer, an object retains its previous state, e.g. stationary or constant linear motion. Mathematically, the energy transfer can be expressed as the product of the force vector, the motion vector, and the cosine of the angle formed. When the force and motion vectors form a perpendicular angle, the product is zero because the cosine of a right angle is zero. The most efficient energy transfer is achieved when the force and motion directions are parallel.
Practically all commercially available bicycles use circular cranks for the riders to pedal the transmission system. With a circular crank, the push force generated by the rider in an upright position on a safety bicycle would be parallel to the pedal motion if the pedal is in front of the pedal rotational axis. Using two pedals, the time that a rider is able to efficiently transfer the pedal force to the crank rotation is approximately one half of the rotation cycle. During the portion of the rotation cycle that efficient power transfer is most difficult, any momentum gained may be partially lost. With a recumbent bicycle, the most efficient power transfer position is different, but the overall efficiency for the pedal cycle is the same.
As can be readily ascertained from the foregoing, various improvements in bicycle design and construction are desirable.
According to various embodiments a human powered ground vehicle can be provided. This vehicle can include a vehicle frame having a forward end and a rearward end and/or a steering column hingedly connected to said vehicle frame and extending across said vehicle frame. The vehicle can also include a motive power input assembly supported by the frame and adapted to derive a motive power from physical exertion of force by a driver. The motive power input assembly can include at least one pedal member adapted to revolve about a laterally extending axis that traverses the vehicle frame through an area located forward of the steering column. The vehicle can also include at least one rear wheel mounted for rotation proximate the rearward end of the vehicle and/or a means for transmitting power from the motive power input assembly to the front wheel, thereby permitting the vehicle to be driven, wherein the means for transmitting power can include a universal joint that can include a first sprocket and a second sprocket, wherein the first sprocket can be rotatably fixed with respect to the vehicle frame and the second sprocket can be pivotable with respect to the first sprocket such that rotation of the first sprocket can cause rotation of the second sprocket. The means for transmitting power can also include a first sprocket assembly that includes at least a third sprocket that can be rotatably fixed with respect to a steering column and/or a drive chain drivingly connecting the second sprocket with the sprocket assembly a second sprocket assembly that can include at least a fourth sprocket fixed with respect to the front wheel and can have a first axis of rotation, wherein the front wheel has a second axis of rotation that is the same as the first axis of rotation. The means for transmitting power can also include a drive chain drivingly connecting the first sprocket assembly to the second sprocket assembly.
The front wheel of the human powered ground vehicle can include an axle. The second axis of rotation can lie along a center line of the axle. The human powered ground vehicle further includes a shock absorber, that has a first end and a second end that is connect to the steering column. The second end can be connected to the wheel. The second sprocket can lie on a second plane, the third sprocket can lie on a third plane, and the fourth sprocket can lie on a fourth plane. The second, third, and fourth planes can be parallel to each other. At least one of the third and fourth sprocket assemblies can include a derailleur system that can include a plurality of sprockets, a guide, and an adjustable chain tensioner.
The human powered vehicle can include a detachable seat that includes a first portion, a second portion, and an interior compartment defined at least in-part by one of the first seat portion and the second seat portion.
According to various embodiments, a method of storing a human powered ground vehicle is provided. The method can include at least one of the steps of: providing a vehicle; separating the seat from the vehicle frame; separating the first seat portion from the second seat portion; folding the vehicle frame to form a folded vehicle frame; placing the folded vehicle frame into the interior compartment; and bringing the first seat portion and the second seat portion together with the folded vehicle frame.
According to various embodiments a human powered ground vehicle, is provided that can include a foldable vehicle frame and a detachable seat. The seat can be detachable from the foldable vehicle frame. The detachable seat can include a first seat portion, a second seat portion, and an interior compartment. The interior compartment can be formed at least in-part by at least one of the first seat portion and the second seat portion. The interior compartment can be of sufficient size and shape to house the foldable vehicle frame when in a folded position. The detachable seat can include at least one roller and/or at least one handle.
According to various embodiments a human powered ground vehicle is provided that can include a reciprocating pedal system that includes at least two roller clutches, a front wheel, a rear wheel, and/or a drive system. The drive system can include two gears a chain and at least two sprockets. The drive system can drivingly connect the reciprocating pedal system and the rear wheel. The drive system can include a derailleur system that includes a plurality of sprockets, a guide, and an adjustable chain tensioner.